I wholeheartedly subscribe to the notion that Twitter—the technology/platform/operating system/infrastructure—is separate from how people use it.

But I found his two comparisons of ball-point pens and using notebooks in public to be one of the most striking examples of a McLuhanesque consequence of a medium like Twitter:

Imagine a world where everyone used typewriters: they write novels, manifestos, historical surveys, and so on, and they do it all using typewriters.
Now the ball-point pen comes along. People use it to write down grocery lists and street addresses and recipes and love notes. What is this awful new technology? the literary users of typewriters say. Ball-point pens are the death of humanism.
Nevermind, of course, that you can use ball-point pens to write whatever you want: a novel, a screenplay, epic poems, religious prophecy, architectural theory, ransom notes. You can draw astronomical diagrams, sketch impossible machines for your Tuesday night art class, or even work on new patent applications for a hydrogen-powered automobile â€“ it doesn’t matter.

He describes Twitter as a note-taking technology. Fair enough. Regardless, you really need to go read the rest.